In U.S. Pat. No. 4,187,059 to Parker, there is disclosed a valve guide construction of an intake valve for use in large multiplex pumps. Reference is made to this previous patent for further background of this invention. As pointed out by Parker, it is desirable that the poppet valve stem in large triplex pumps be axially aligned vertically while lateral support is provided for the poppet valves.
It is necessary that the intake valve in such a multiplex pump have the inner valve stem portion guided within a valve guide located inside the flow area of the pump fluid end. The valve guide must be removable from the fluid end for repairs or replacement of the valve member, and at the same time the valve guide must be easily placed within the fluid end and oriented to provide rigid, dependable valve guiding. Reference is made to U.S. Pat. No. 4,468,174 for further background of a multiplex pump suitable for helicopter transportation.
In a multiplex pump there is limited space for working on the fluid end of the pump. Provision must be made for removing the discharge valve vertically upward, and removing the suction valve rearwardly from the fluid end. The tremendous pressures developed within the fluid end of a multiplex pump requires that there be a minimum of sharp corners and drilled and threaded holes because of stress risers. It would therefore be desirable to have an improved fluid end for a multiplex pump that incorporated a minimum number of stress risers therein so that the fluid end could be built of a minimum size and weight as compared to fluid ends that must necessarily be made massive due to the numerous threaded holes and sharp edges that result in the unwanted stress risers.
Two Roughnecks require several hours of time in order to replace the intake valve assembly of most prior art multiplex pumps. Therefore, it would be desirable to be able to more rapidly service the intake check valve of a triplex mud pump in order to reduce the down time required for field repairs.
The present invention contemplates improvements in the fluid end of a multiplex pump by the provision of a valve guide bracket that enables access to an intake valve assembly in a manner to allow the valve to be removed rearwardly from the fluid end in opposition to the reciprocating piston, and which vertically aligns the valve stem and places the valve assembly within the variable chamber of the fluid end of the pump.